1. Field of the Invention
The invention is directed to an improved unipolar transverse flux machine.
2. Description of the Prior Art
One unipolar transverse flux machine, proposed in German Patent Disclosure DE 100 39 466.3, which was not published by the priority date of the present application, has the advantage of a simple modular construction, in which with an increasing number of modular units, each composed of one stator module and one rotor module, the concentricity of the machine is improved. With 1-phase and 2-phase machines, that is, with one or two modular units, the torque course exhibits a pronounced waviness, known as torque rippling.
In a microstepping control motor with a disk rotor (U.S. Pat. No. 4,629,916), it is known, by displacement of the position of symmetrical pole pitches, to reduce the harmonic content with respect to certain harmonics, or to suppress certain harmonics entirely. The amount a of the displacement in electrical degrees determines which one of the harmonics is suppressed and conforms to the equation α=Π/ν, where ν is the ordinal number of the suppressed harmonic.
In an identical known microstepping control motor (German Patent Disclosure DE 37 13 148 A1), first the radial center lines of the stator poles are spaced apart from one another by 360 electrical degrees, and as a result the highest efficiency is achieved. As a result, however, the proportion of torque dictated by harmonics is also maximized. To reduce the harmonic content, the stator poles are now offset individually and by various amounts from their center lines defined by the pole pitch, and the effect of the offset is calculated for each individual position, in terms of its effect on the outset torque, that is, on the magnitude of the resultant fundamental torque and of the proportion of harmonics.